Mail Stop 6010	February 23, 2006

Mr. Thomas B. King
President and Chief Executive Officer
Alexza Pharmaceuticals, Inc.
1020 East Meadow Circle
Palo Alto, California 94303

Re:	Alexza Pharmaceuticals, Inc.
      Amendment No. 2 to Registration Statement on Form S-1, file
no.
333-130644
February 15, 2006

Dear Mr. King:

      We have reviewed your filing and have the following
comments.
Where indicated, we think you should revise your document in
response
to these comments.  If you disagree, we will consider your
explanation as to why our comment is inapplicable or a revision is
unnecessary.  Please be as detailed as necessary in your
explanation.
In some of our comments, we may ask you to provide us with
supplemental information so we may better understand your
disclosure.
After reviewing this information, we may or may not raise
additional
comments.

      Please understand that the purpose of our review process is
to
assist you in your compliance with the applicable disclosure
requirements and to enhance the overall disclosure in your filing.
We look forward to working with you in these respects.  We welcome
any questions you may have about our comments or on any other
aspect
of our review.  Feel free to call us at the telephone numbers
listed
at the end of this letter.

Risk Factors

If our product candidates do not meet safety and efficacy
endpoints .
.. . .  Pages 10-11

1. We note your general statement that the 3% device failure rate
in
your Phase IIa clinical trial of AZ-001 "impacted the results of
this
trial."  We also note that you do not discuss any details of the
impact of this device failure in the Business section on page 57.
Please expand your disclosure here and in the Business section to
discuss the impact of this device failure in reasonable detail.


Dilution, page 35
2. Please revise to start with your historical net tangible book
value.

Management`s Discussion and Analysis, page 39
Critical Accounting Estimates and Judgments, page 43
Stock-Based Compensation, page 44
3. Refer to your response to our comment 9. Please include
quantitative factors such as the estimated fair value of your
common
stock in April, October, and December 2005 in your discussion.
Clarify the reasons each significant factor contributed to the
difference between the fair value as of the date of each grant and
the estimated IPO price. For example, (a) describe the continuing
clinical development of your product candidates in April 2005 or
cross reference to a discussion included elsewhere in the filing
as
applicable, and (b) describe the results of your Phase IIa
clinical
trial of AZ-001.

Business

AZ-001, pages 56-58

4. Please revise to disclose the p values for the positive trends
for
the treatment of nausea and sensitivity to sound discussed on page
57.

Manufacturing, pages 62-63

5. Please revise your disclosure regarding the Autoliv agreement
to
disclose that you and Autoliv have agreed to contribute $2,500,000
each toward the development efforts.  We note your statement to
this
effect in footnote 17 to the financial statements.

Registration Rights, page 96

6. Please revise to clarify that the registration rights are on a
best efforts basis as stated in your response to comment 13.

Financial Statements

Note 2. Summary of Significant Accounting Policies
Stock-based compensation, F-16

7. Refer to our comment 12.  Please revise to include all the
information previously requested individually by grant date as was
included in your table in comment 32 in your January 24, 2006
response.

      As appropriate, please amend your filing in response to
these
comments.  You may wish to provide us with marked copies of the
amendment to expedite our review.  Please furnish a cover letter
with
your amendment that keys your responses to our comments and
provides
any requested supplemental information.  Detailed cover letters
greatly facilitate our review.  Please understand that we may have
additional comments after reviewing your amendment and responses
to
our comments.

      We will consider a written request for acceleration of the
effective date of the registration statement as a confirmation of
the
fact that those requesting acceleration are aware of their
respective
responsibilities under the Securities Act of 1933 and the
Securities
Exchange Act of 1934 as they relate to the proposed public
offering
of the securities specified in the above registration statement.
We
will act on the request and, pursuant to delegated authority,
grant
acceleration of the effective date.

      We direct your attention to Rules 460 and 461 regarding
requesting acceleration of a registration statement.  Please allow
adequate time after the filing of any amendment for further review
before submitting a request for acceleration.  Please provide this
request at least two business days in advance of the requested
effective date.

      You may contact Sasha Parikh at (202) 551-3627 or Mary Mast
at
(202) 551-3613 if you have questions regarding comments on the
financial statements and related matters.  Please contact Sonia
Barros at (202) 551-3655 or Suzanne Hayes at (202) 551-3675 with
any
other questions.

								Sincerely,



								Jeffrey P. Riedler
								Assistant Director

cc:	James C. T. Linfield, Esq.
	Brent D. Fassett, Esq.
	Cooley Godward LLP
	380 Interlocken Crescent, #900
	Broomfield, Colorado 80021


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Mr. Thomas B. King
February 23, 2006
Page 3